Rational design of hydrocarbon-based sulfonated copolymers for proton

exchange membranes

Lunyang Liua,b, Wenduo Chena, Tingli Liua,c, Xiangxin Konga,c, Jifu Zhenga and

Yunqi Lia,c†

a Key Laboratory of High-Performance Synthetic Rubber and its Composite Materials

& Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied

Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; b

University of Chinese Academy of Sciences, Beijing 100049, PR China; c University

of Science and Technology of China, Hefei 230026, China

† To whom correspondence should be addressed. E-mail: yunqi@ciac.ac.cn. Phone:

+86 (0)431 85262535

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2019

Fig. S1. Probability density function(PDF) for (a) proton conductivity(), (b) methanol permeability(MePerm), (c) the degradation temperature at 5% weight loss (Td5) and (d) tensile modulus(TM) of hydrocarbon-based sulfonated copolymer PEMs . Highlighted region with preferred significance (Lsig) of 0.05.

Fig. S2 Optimal combination of features to predict each of the (a) σ, (b) Td5, (c) MePerm and d (TM) four performance indexes. RMSE against the generation of GA was plotted in 5-fold cross validation for training and test. Red points refer to testing performance and blue points are training performance.

Fig. S3 Pearson (CORRp, lower triangle) and Spearman (CORRsp, upper triangle) correlation matrix for the selected features to predict (a),Td5 (b), MePerm (c), TM (d), respectively.

Fig. S4 Ranking of feature importance(blue circle) using RF models, Pearson Rp(black diamond) and Spearman Rsp (yellow square) correlation coefficients between features and performance indexes for (a), Td5(b), MePerm(c), TM(d).

Fig. S5. The violin plots of the distributions of performance indexes contributed from the monomers in each cluster. ANOVA analysis of hydrophilic (a, b c, d) and hydrophobic (a´, b´, c´, d´) clusters. The box and violin plots show the distribution of membrane properties (σ, Td5, MePerm and TM) in each cluster.

Fig. S6. Screening copolymers for σ (a), Td5(b), MePerm(c), TM(d) with RF model. The RF predicted performance indexes are mapped onto the color. The dashed vertical line separate hydrophilic monomer into four clusters, cli1 to cli4 from left to right using the same order as shown Fig. 3c. The x, y axis are monomer IDs which are presented in Table S1 and S2 in supporting information.

Fig. S7 Copolymer screening results of σ (a), Td5(b), MePerm(c), TM(d) with LR model. Each identical copolymer represented by a unique block and the predicted performance index are mapped onto the color of block. The dashed vertical line separate hydrophilic monomer into four clusters, the same order as shown Fig. 3c. The x, y axis are monomer IDs which are presented in Table S1 and S2.

Tables

Table S1 List of hydrophilic monomers.

ID Name ID Name

1 S-PEEK-1 84 SEF

2 SPAEK-40 85 SPE4

3 SPAEKKS-1 86 SN30

4 SPAEK-X15Y4 87 SMP-PAEK-90

5 X4Y4 88 SPAES-1

6 SPEEKK-10 89 LSPA-0.49

7 sPAS-7/3 90 S2-PAES-40

8 SPEEKK-60 91 BM-1

9 PAES-2S-b60 92 SPAEK40-TRI

10 SPAE-9 93 SC-SPAE90

11 1a 94 PAEN80

12 SPI-B1 95 SPPBI-20

13 sPBI-60 96 SPI-4a

14 DQB50 97 SPI-4b

15 8a 98 SPI-8(50)

16 SPI-40 99 SPI-8-p

17 SPI-30 100 SPI-4c

18 II-b 101 SPI-4d

19 S-75 102 SPEKEBI-1

20 SPI 40 103 SPI-2.2

21 P-DTN70 104 SCT-SAPs-0.8

22 DAN-50 105 6F-SNPAEK-50

23 DHNH40 106 2-SPAES-50

24 DQN40 107 4-SPAES-25

25 SPBIBI-a(70) 108 SOPAES-0.3

26 SPBIBI-b(70) 109 M10N5-SO3H

27 SPPQ-80 110 SPAES-25

28 SPPQ(o)-80 111 SPFENO-20

29 SPI-1 112 D-SPAEENH-30

30 dsPPEPO-70 113 m-SPAEENH-50

31 SPI-N1 114 P-SPAEENH-50

32 SPAEK-20-COOH

115 SPI90-TFVBPA10

33 S-FPEK(HF90) 116 CSPI90-6FATFVP10

34 NB-90 117 sPBT70

35 IBQS-20 118 sPBT-PE52.5

36 S4-PAES-30 119 P1-1.0

37 SPE1 120 SPAE20

38 SPAEK-20-BI 121 If-60

39 sPEKkP-450 122 sPBT-6FA45

40 PAES-2S-a60 123 SPBT-PS50

41 3a-1 124 SPBT-6F70

42 3b-1 125 S-PES-40

43 S4PH-20-PS_1 126 B20V80-SDPA

44 S4PH-20-PS_2 127 SPES-C-70

45 SMPES-15 128 SPPBP20

46 SPAEEKK-B90 129 SPEES-10

47 4-PES-30 130 S-APES-20

48 semi-SPEK-12 131 SPP-1

49 SPI-1.88 132 SPAES-HQ-40

50 6F-PAEK-SP22 133 HQSH-20

51 S4-PAES-20 134 SPAEPO-55

52 SPES-25-TPD 135 sPATPO-60

53 S2-PAES-30 136 SPTPOF-60

54 SPES-1 137 tsPTPO-80

55 sPBI-NA50 138 tsPEPOF-100

56 sPBI-30 139 DsPEPOF-100

57 2F-SPAES-20 140 sPESPO-30

58 SPEEKK-1 141 SPE2

59 OBA-40 142 DHDPE40

60 PTEHSH-60 143 6F-BPA40

61 PTHQSH-60 144 BPAQS-20

62 PTAQSH-50 145 1

63 SPTA-50 146 SP35

64 PTFQSH-70 147 6FBPAQSH-20

65 PTATSH60 148 SPSSF30

66 SPTA1 149 6FBPAQSH-0-20

67 PAQS-30 150 SPAES-6FBPA-40

68 SPA-0-70 151 SPAES

69 SPA-70 152 SEB

70 HPPQSH-10PS 153 M-30

71 sPAEPO-60 154 C-SPAEK-40

72 sPEKP-350 155 BP-1

73 SPE3 156 SPAEKBO-10

74 HPPQSH-10 157 SPAEK-6F-20

75 1-tSPPco-PAEK-1.0

158 HFAS82

76 PSA-SPAE-80 159 SPEN-40

77 SPAE-1 160 B20P80

78 SPAEK-60 161 NPI(1)/SPP(40)

79 HS-PAEK-10 162 Ia-70

80 TS-0-PAEK-15 163 SPA-0.49

81 TS-PAEK-15 164 PFMPP5-r-PFSPP5

82 DHN40 165 3a

83 SPAES-PQ-20 166 PBOS2-r-PSBOS8

Table S2 List of hydrophobic monomers.

ID Name ID Name

1 SPFENO-20 89 8a

2 sPAEPO-60 90 SPI-40

3 SPE3 91 SPI-N2

4 SPEN-40 92 SPI-4a

5 dsPPEPO-70 93 P1-1.0

6 SPAEK-20-COOH

94 SPAE20

7 OBA-40 95 PBOS2-r-PSBOS8

8 sPEKP-350 96 B20P80

9 M10N5-SO3H 97 SPP-2

10 3a 98 SPP-3

11 SPAEK40-TRI 99 SPI-10

12 BM-1 100 SPI-B5

13 SPAEEKK-H90 101 I-40

14 sPEKkP-450 102 FSPPI-50

15 SPEEKK-1 103 Ic-70

16 SPE1 104 If-60

17 2F-SPAES-20 105 LSPA-0.49

18 SPAEK-X15Y4 106 SPA-0.49

19 SPBT-PS50 107 SPTPOF-60

20 SCT-SAPs-0.8 108 DsPEPOF-100

21 NB-90 109 tsPTPO-80

22 SPAEEKK-B90 110 sPATPO-60

23 PTATSH60 111 sPESPO-30

24 PTAQSH-50 112 SPE2

25 PTFQSH-70 113 SPES-25-TPD

26 X4Y4 114 SPAEPO-55

27 BPAQS-20 115 4-PES-30

28 6FBPAQSH-20 116 SMPES-15

29 PTEHSH-60 117 SPES-1

30 PTHQSH-60 118 6F-BPA40

31 sPBI-SF70 119 S4PH-20-PS

32 SPEKEBI-1 120 SPSSF30

33 sPBI-30 121 PAES-2S-a60

34 SPPI-60 122 PSA-SPAE-80

35 sPBI-NAA70 123 S2-PAES-40

36 sPBI-NA50 124 SPAES-6FBPA-40

37 sPBI-60 125 2-SPAES-50

38 SPTA3 126 1

39 SPA-0-70 127 S-APES-20

40 SPA-70 128 SPAES-25

41 SPI-9 129 SOPAES-0.3

42 SPI90-TFVBPA10

130 SP35

43 CSPI90-6FATFVP10

131 SPEES-10

44 Id-70 132 SPAES-HQ-40

45 Ia-70 133 HQSH-20

46 Ib-70 134 SPBT-6F70

47 DHNH40 135 SPBT-6F55

48 SPI-N1 136 sPBT70

49 DAN-50 137 sPBT-PE52.5

50 DThioN70 138 SPPBP20

51 DPyN70 139 SPAEN-1

52 M-DTN70 140 SEB

53 P-DTN70 141 SPAE-1

54 DQN40 142 m-SPAEENH-50

55 SPI-N3 143 PAEN80

56 NPI(1)/SPP(40) 144 SN30

57 SPI-30 145 PFMPP5-r-PFSPP5

58 S-75 146 SPP-1

59 DQB50 147 SPP-60

60 1a 148 B20V80-SDPA

61 IBQS-20 149 3a-1

62 SPI-B2 150 SPAE-9

63 SPBIBI-b(70) 151 6F-PAEK-SP22

64 SPI-B1 152 TS-PAEK-15

65 SPI-B3 153 6F-SNPAEK-50

66 HPPQSH-10PS 154 BP-1

67 SPPQ-80 155 SPI-1.88

68 SPPQ(o)-80 156 SMP-PAEK-90

69 SPBIBI-a(70) 157 SPAEK-60

70 1-tSPPco-PAEK-1.0

158 SPEEKK-10

71 HPPQSH-10 159 M-30

72 SPPBI-20 160 semi-SPEK-12

73 PAQS-30 161 C-SPAEK-40

74 SPAEK-20-BI 162 SPTA1

75 SPAEK-40 163 SPTA-50

76 SPAEKKS-1 164 sPAS-7/3

77 SPEEK-60 165 S2-PAES-30

78 S-PEEK-1 166 DHN40

79 SPAEKBO-10_1 167 PAES85

80 SPAEKBO-10_2 168 SPAES-PQ-20

81 S-FPEK(HF90) 169 SEF

82 SPI-2.2 170 SPAES-1

83 TPPO-40 171 SES

84 II-50 172 SPAES

85 SPI-8-m 173 S-PES-40

86 SPI-8(50) 174 SPE4

87 SPI-8-p 175 HFAS82

88 SPI-1

Table S3. Statistical summary of performance indexes of hydrocarbon-based sulfonated copolymer PEMs. Threshold is the value for binary classification, and value at Lsig is the cutoff value of a performance index where a solution is preferred at Lsig significance level.

Properties Records Min. Mean Max. Threshold

Value at Lsig

(S/m) 589 0.004 8.9 29.8 9.4 21.1

MePerm(10-7cm2/s) 211 0.005 4.0 21.1 3.8 0.1

WU(%) 607 1.8 47.3 670.0 30.8 120.2

SR(%) 427 7.1 17.7 240.0 18.6 50.0

Tg(oC) 148 107.0 229.2 324.0 240.6 294.4

Td5(oC) 385 44.7 312.8 537.0 328.4 459.3

TS(MPa) 395 5.9 49.8 123.0 52.3 85.4

TM(GPa) 312 0.01 1.3 4.5 1.6 2.4

EAB(%) 396 1.3 27.5 247.1 28.9 101.6

Table S4. Features for modeling performance index of copolymers. Bold features with a, b, c, d superscript were used to construct predictive models for σ, Td5, MePerm and TM, respectively.

ID Label Description

1 FraLic Fraction of hydrophilic monomers in copolymer

2 IECa,c Ion exchange capacity of copolymer

3 Ta Temperature for measurements

4 RHa Relative humidity

5 clogPb Calculated LogP value

6 MaxAbsPartialChargea,b,c,d Theoretic charge value for fully dissociated or protonated monomer

7 MinEStateIndexb,c EState indices for the molecule, encode electronic and topological information

8 MaxEStateIndexb EState indices for the molecule, encode electronic and topological information

9 MinAbsEStateIndexb,c EState indices for the molecule

10 BalabanJb,c Balaban's connectivity topological index

11 Ipca,b,c,d the information content of the coefficients of the characteristic polynomial of the adjacency matrix of a hydrogen-suppressed graph of a molecule.

12-20 PEOE_VSA1b,d,2b,d,3b,c,6a,7,8b,9a,b,d,10b,11a,b,c

MOE-type descriptors using partial charges and surface area contributions

21-24 SMR_VSA5d,6a,9b,d,10d MOE-type descriptors using molecular refractivity contributions and surface area contributions

25-29 SlogP_VSA1c,d,2d,5b,d,8d,12a,b,c,d MOE-type descriptors using LogP contributions and surface area contributions

30-37 EState_VSA2d,3b,4,5,6a,7,8,9 MOE-type descriptors using EState indices and surface area contributions

38-39 VSA_Estate9d,10d MOE-type descriptors using EState indices and surface area contributions

40 FractionCSP3b The fraction of C atoms with SP3 hybrid orbital, i.e., C in sigma bonds

41 NHOHCountb,d Number of NH or OH groups

42 NumHAcceptorsc Number of Hydrogen Bond Acceptors

43 NumRotatableBondsd Number of Rotatable Bonds, i.e., sigma bonds

44 fr_C_O_noCOOa,b,c Number of oxygen atoms in carbonyl group excluding COOH

45 fr_NH0a,b,d Number of Tertiary amines

46 fr_NH1a,b,c,d Number of Secondary amines

47 fr_alkyl_halidea,c,d Number of alkyl halides

48 fr_amidea,d Number of amides

49 fr_bicyclicb,d Number of Bicyclic

50 fr_ethera,b Number of ether oxygens (including phenoxy)

51 fr_ketonea,b,c,d Number of ketones

52 fr_para_hydroxylationa,b,c,d Number of para-hydroxylation sites

53 fr_phenol_noOrthoHbondb,c,d Number of phenolic OH excluding ortho intramolecular Hbond substituents

54 fr_pyridineb,c Number of pyridine rings

55 fr_sulfonea,d Number of sulfonic groups